Spectrometric characterization of X- rays and DTA to corrosion products of storage tank and petroleum pipelines

Abstract

In the Oil Industry, corrosion products of different properties and morphologies are originated because the steel meets the accompanying water. The objective research is to characterize corrosion products by techniques of X-ray spectrometry and differential thermal analysis (DTA). Samples were obtained under operating conditions in an oil pipeline and storage tank. The results showed that the pipeline elemental composition is more heterogeneous than the sample tank. Chemical elements appear that indicate the formation of iron oxides, salts of iron chlorides, magnesium. In the case of the tank, there is only presence of carbon, oxygen, sulfur and iron, which suggest the formation of sulfur and iron sulphates. X-ray spectrometry showed that the overall composition of the pipeline corrosion products have a greater compositional variability than those of the crude storage tank. The differential thermal analysis showed that a greater variety of crystalline phases was obtained in the pipeline than in the crude storage tank. In both systems, the presence of ferrihydrite was detected where the highest percentage of mass loss, iron sulphides for the tank steel and additional silicates and iron sulphates for the pipeline were reached. The results showed that there is correspondence with the composition of the steels, the corrosive medium and the phases determined by the techniques used.